1. Field of the Invention
The innovations here disclosed concern the tail-cones of aircraft, specifically, modifications to their traditional composition and design intended to improve their serviceability and longevity.
2. Related Art
Inside the tail-cone of an aircraft reside the cables connected to and controlling the rudder, and the push-rod which is connected to and controlling the elevators. Inspection of these cables and push-rod is required upon completion of each one hundred hours of flying time. Taking as examples the Cessna 335 and 340 aircraft, access to these cables requires the removal of the tail-cone from the body of the aircraft. Frequent removal and reinstallation of a tail-cone is time consuming and expensive and entails significant wear and tear to the cone itself. Generally composed of aluminum or ABS plastic, a tail-cone is fragile, even brittle, and breakage is common.
Again, using the Cessna 335 and 340 aircraft as examples, broken tail-cones are replaced by two-piece ABS replacement cones supplied by the manufacturer. Cable inspection is then accomplished by removal of one of the tail-cone's two pieces. Composed of ABS plastic, this piece is quite brittle and vulnerable to wear and tear. This two piece tail-cone consists of a top piece meeting a bottom piece at a generally horizontal seam, with the two pieces being bolted to the rear of the plane underneath the rudder and around the rear of the elevators. The manufacturer is reported to mold a one-piece tail-cone and then cut it from front to back along a generally horizontal line, starting at the center of the left and right elevator fairings (F) in FIG. 2 and extending back and down slightly to finish the cut below the tail light housing (L) at the far rear of the tail-cone. The manufacturer then expects the aircraft maintenance personnel to bolt the two pieces onto the plane. The position of the bottom piece, designated for removal during inspection, is beneath and in close proximity to the elevators or "tail flaps", making removal difficult. Therefore, breakage of this two-piece tail-cone is still common.
Because of the difficulty of certifying new small airplanes and modifications to old airplanes, there are still many of the older planes in use. The Cessna 340 tail-cone fragility and inspection problem has long been, and continues to be, a serious problem for smaller commercial and private aircraft owners and operators. Therefore, there has been a long-time need for improvement in the tail-cone design to allow less expensive and less damaging inspections.